Evaluating the effectiveness of restoring longitudinal connectivity for stream fish communities: towards a more holistic approach

A more holistic approach towards testing longitudinal connectivity restoration is needed in order to establish that intended ecological functions of such restoration are achieved. We illustrate the use of a multi-method scheme to evaluate the effectiveness of ‘nature-like’ connectivity restoration for stream fish communities in the River Deerness, NE England. Electric-fishing, capture-mark-recapture, PIT telemetry and radio-telemetry were used to measure fish community composition, dispersal, fishway efficiency and upstream migration respectively. For measuring passage and dispersal, our rationale was to evaluate a wide size range of strong swimmers (exemplified by brown trout Salmo trutta) and weak swimmers (exemplified by bullhead Cottus perifretum) in situ in the stream ecosystem. Radio-tracking of adult trout during the spawning migration showed that passage efficiency at each of five connectivity-restored sites was 81.3–100%. Unaltered (experimental control) structures on the migration route had a bottle-neck effect on upstream migration, especially during low flows. However, even during low flows, displaced PIT tagged juvenile trout (total n = 153) exhibited a passage efficiency of 70.1–93.1% at two nature-like passes. In mark-recapture experiments juvenile brown trout and bullhead tagged (total n = 5303) succeeded in dispersing upstream more often at most structures following obstacle modification, but not at the two control sites, based on a Laplace kernel modelling approach of observed dispersal distance and barrier traverses. Medium-term post-restoration data (2–3 years) showed that the fish assemblage remained similar at five of six connectivity-restored sites and two control sites, but at one connectivity-restored headwater site previously inhabited by trout only, three native non-salmonid species colonized. We conclude that stream habitat reconnection should support free movement of a wide range of species and life stages, wherever retention of such obstacles is not needed to manage non-native invasive species. Evaluation of the effectiveness of fish community restoration in degraded streams benefits from a similarly holistic approach

Quantifying the fine-scale behaviour of spawning run river lamprey (Lampetra fluviatilis) approaching a low-head weir retrofitted with studded tiles

Fish passes (or fishways) designed to mitigate for the impeded movement of migratory fish at anthropogenic structures (such as dams and weirs) often function poorly. This is particularly the case for anguilliform species such as lamprey (Petromyzon spp. and Lampetra spp.). Poor swimming capability (in comparison to e.g. salmonids) and a lack of understanding of behaviour in response to hydrodynamic cues are considered key reasons limiting the performance of mitigation measures. A field study employing Passive Integrated Transponder (PIT) and fine-scale (sub-metre) acoustic telemetry was conducted on the River Derwent (Yorkshire, UK) in Winter (November – December) 2017. The aim of the study was to assess river lamprey behaviour and passage at a low-head weir retrofitted with studded tiles designed to aid upstream movement. In this talk, the acoustic telemetry data will be presented, outlining fine-scale behaviour and weir approach routes of lamprey in relation to hydrodynamics that were measured using a remotely operated Acoustic Doppler Current Profiler. How this data can be quantified into “behavioural rules” to parameterise Agent Based Models will be discussed and examples provided. Such models will enable better predictions of fish movements to be made as they encounter anthropogenic structures and guide the design of more effective mitigation measures, such as fish passage and screening systems

The Superorganism: Problems and Perspectives

This article aims to contribute to recent debates on research methods in public administration by examining the use of quantitative methods in public administration research. We analyzed 1,605 articles published between 2001–2010 in four leading journals: Journal of Public Administration Research and Theory (JPART), Public Administration Review, Governance, and Public Administration (PA). Results show that whereas qualitative methods are still predominant compared to quantitative methods (56% versus 44%), the field is becoming increasingly quantitative. Of quantitative methods used, surveys are most dominant, while a combination of methods is used far less often. In general, very few studies use a mixed methods design. As to the areas of research, we found that the use of quantitative methods is unequally distributed; some subfields (public management) use quantitative methods more often than others (policy and politics), and some journals (JPART, PA) publish articles on quantitative research more than others (Governance). Implications for public administration research are discussed

Gaining Insight into Determinants of Physical Activity using Bayesian Network Learning

Contains fulltext : 228326pre.pdf (preprint version ) (Open Access) Contains fulltext : 228326pub.pdf (publisher's version ) (Open Access)BNAIC/BeneLearn 202

The effects of work alienation and policy alienation on behavior of public employees

Public employees are confronted with various pressures, such as increased work demands and the need to implement controversial policies. This study uses work alienation and policy alienation models to analyze work and policy pressures. Based on a survey of 790 respondents, it was firstly found that work alienation results in less work effort and more intention to leave. Secondly, policy alienation negatively impacts behavioral support for a policy and the intention to implement it. These results suggest that work alienation and policy alienation have different –but both important– effects on (intended) behavior on the job

De “ultieme HRM-vraag”: Zou jij je werkgever aanbevelen aan familie en vrienden?

Organisaties streven daarom naar 'loyale' werknemers. Er zijn al verschillende manieren om loyaliteit te meten, zoals via 'organisatiebetrokkenheid'. Maar is er niet één ultieme vraag die we kunnen stellen? Misschien kunnen we deze loyaliteit meten via de zogenaamde 'Werkgever Net Promotor Score'. Deze vraag is afgeleid van het artikel van Frederick Reichfeld uit de Harvard Business Review, getiteld "The one number you need to grow". Reichfeld stelt er een 'ultieme vraag' is die bedrijven aan hun klanten kunnen stellen. Deze vraag: "In welke mate beveelt u deze organisatie aan bij vrienden en familie?" wordt in klanttevredenheidsonderzoeken gebruikt gebruikt om de loyaliteit van klanten te meten

Consistent alleviation of abiotic stress with silicon addition: a meta-analysis

1. Hundreds of single species studies have demonstrated the facility of silicon (Si) to alleviate diverse abiotic stresses in plants. Understanding of the mechanisms of Si-mediated stress alleviation is progressing, and several reviews have brought information together. A quantitative assessment of the alleviative capacity of Si, however, which could elucidate plant Si function more broadly, was lacking. 2. We combined the results of 145 experiments, predominantly on agricultural species, in a meta-analysis to statistically assess the responses of stressed plants to Si supply across multiple plant families and abiotic stresses. We interrogated our database to determine whether stressed plants increased in dry mass and net assimilation rate, oxidative stress markers were reduced, antioxidant responses were increased and whether element uptake showed consistent changes when supplied with Si. 3. We demonstrated that across plant families and stress types, Si increases dry weight, assimilation rate and chlorophyll biosynthesis and alleviates oxidative damage in stressed plants. In general, results indicated that plant family (as a proxy for accumulator type) and stress type had significant explanatory power for variation in responses. The consistent reduction in oxidative damage was not mirrored by consistent increases in antioxidant production, indicative of the several different stress alleviation mechanisms in which Si is involved. Silicon addition increased K in shoots, decreased As and Cd in roots and Na and Cd in shoots. Silicon addition did not affect Al, Ca or Mn concentration in shoots and roots of stressed plants. Plants had significantly lower concentrations of Si accumulated in shoots but not in roots when stressed. 4. Meta-analyses showed consistent alleviation by Si of oxidative damage caused by a range of abiotic stresses across diverse species. Our findings indicate that Si is likely to be a useful fertilizer for many crops facing a spectrum of abiotic stresses. Similarities in responses across families provide strong support for a role of Si in the alleviation of abiotic stress in natural systems, where it has barely been explored. We suggest this role may become more important under a changing climate and more experiments using non-agricultural species are now needed

Session C7: Tricky Little Lampreys! Efficacy of an Unmodified and Modified Super-Active Baffle Fish Pass for European River Lamprey (Lampetra Fluviatilis)

Abstract: Achieving good upstream passage of lampreys, a threatened group of serpentine fishes, remains a problem. The ability of European river lamprey (Lampetra fluviatilis) to pass a Crump weir using a 15% gradient Larinier superactive baffle fish pass during their upstream spawning migration was tested. This type of fish pass has become widespread in Europe in the last two decades, but its efficiency for river lamprey is unknown. River lamprey were PIT tagged (n=350) PIT, a subsample were acoustic tagged (n=31), and all were released downstream in batches in Oct-Dec 2013. Telemetry arrays were installed in the pass (PIT) and river (acoustic) and ran throughout the migration period. Attraction efficiency into the fishway (estimated at 90.1%) was good and half of lampreys entered within 24 h of release, but only one lamprey successfully ascended the pass (0.3% passage efficiency), despite many entering repeatedly. Out of 29 acoustic tagged lamprey that visited the weir, four (13.8%) passed the weir directly. The fishway was unsuitable for river lamprey over a wide range of flows. The pass was modified by addition of vertically mounted peg-and-slot tiles, interrogated at the entrance and exit by PIT telemetry and retested in winter 2014- 15. There was an increase in passage success. Preliminarily, out of 197 river lamprey PIT tagged Oct-Dec 2014, 184 (93.4%) were logged at the fishway entrance. 74 (40.2%) entered the tiles at the downstream end, of which 14 (18.9%) swam up through the tiles successfully. Twelve lamprey (6.5% passage efficiency) were logged at the upstream exit of the pass. Reduced flow velocity in combination with increased availability of resting habitat within the tiles may increase the passage efficiency of this type of fish pass for river lamprey. Although increased, passage efficiency, after placement of the tiles, is still considered far from optimal

Skin dendritic cells in melanoma are key for successful checkpoint blockade therapy.

BACKGROUND: Immunotherapy with checkpoint inhibitors has shown impressive results in patients with melanoma, but still many do not benefit from this line of treatment. A lack of tumor-infiltrating T cells is a common reason for therapy failure but also a loss of intratumoral dendritic cells (DCs) has been described. METHODS: We used the transgenic tg(Grm1)EPv melanoma mouse strain that develops spontaneous, slow-growing tumors to perform immunological analysis during tumor progression. With flow cytometry, the frequencies of DCs and T cells at different tumor stages and the expression of the inhibitory molecules programmed cell death protein-1 (PD-1) and T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) on T cells were analyzed. This was complemented with RNA-sequencing (RNA-seq) and real-time quantitative PCR (RT-qPCR) analysis to investigate the immune status of the tumors. To boost DC numbers and function, we administered Fms-related tyrosine 3 ligand (Flt3L) plus an adjuvant mix of polyI:C and anti-CD40. To enhance T cell function, we tested several checkpoint blockade antibodies. Immunological alterations were characterized in tumor and tumor-draining lymph nodes (LNs) by flow cytometry, CyTOF, microarray and RT-qPCR to understand how immune cells can control tumor growth. The specific role of migratory skin DCs was investigated by coculture of sorted DC subsets with melanoma-specific CD8+ T cells. RESULTS: Our study revealed that tumor progression is characterized by upregulation of checkpoint molecules and a gradual loss of the dermal conventional DC (cDC) 2 subset. Monotherapy with checkpoint blockade could not restore antitumor immunity, whereas boosting DC numbers and activation increased tumor immunogenicity. This was reflected by higher numbers of activated cDC1 and cDC2 as well as CD4+ and CD8+ T cells in treated tumors. At the same time, the DC boost approach reinforced migratory dermal DC subsets to prime gp100-specific CD8+ T cells in tumor-draining LNs that expressed PD-1/TIM-3 and produced interferon γ (IFNγ)/tumor necrosis factor α (TNFα). As a consequence, the combination of the DC boost with antibodies against PD-1 and TIM-3 released the brake from T cells, leading to improved function within the tumors and delayed tumor growth. CONCLUSIONS: Our results set forth the importance of skin DC in cancer immunotherapy, and demonstrates that restoring DC function is key to enhancing tumor immunogenicity and subsequently responsiveness to checkpoint blockade therapy